Efforts toward drug discovery continue to use vast technical and financial resources to identify and develop new and useful drugs. Unfortunately, finding new drugs has continued to be difficult. For example, development of less damaging, more precisely targeted cancer therapies is essential. But even after decades of research, scientists still struggle to identify therapeutic compounds with the right mix of medicinal and cancer-targeting properties which not only reduce the likelihood that a therapeutic compound could serve as a treatment strategy but creates a need for successful methods of surgical resection.
A wide variety of types of compounds have been studied and pursued for a large breadth of therapeutic purposes. For example, small chemical molecules and larger biologics (e.g., antibodies) have been used for a plethora of therapeutic applications with varied success. Some smaller peptides have also been shown to be useful as drugs, e.g., by virtue of their natural potency.
A lack of methods for rapid and efficient production of peptides and proteins for clinical applications has limited the discovery of peptides and proteins that might serve as therapeutic compounds. Creating fusions of peptides, protein domains, or proteins, to a different protein to enhance production of peptides and proteins has been explored in bacterial expression systems, e.g., E. coli gene expression. However, bacterial protein expression systems are generally limited due to errors in protein folding efficiency. Thus, there is still a need for methods enabling the rapid and efficient production of peptides, protein domains, and proteins.